Surface Areas of Spheres Recognize and define the basic properties of speres. Find surface areas of spheres. Scenes such as reflective spheres over a checkerboard plane can be generated using computer ray-tracing.
PROPERTIES OF SPHERES A segment with endpoints that are the center of the sphere and on the sphere is a radius of the sphere. A chord of the sphere is a segment with endpoints that are on the sphere. A chord that contains the center of the sphere is a diameter of the sphere. A tangent to a sphere is a line that intersects the sphere in exactly one point.
PROPERTIES OF SPHERES Hemisphere Great Circle
Key Concept Surface Area of a Sphere If a sphere has a surface area of T square units and a radius of r units, then T = 4r2 r
Example 1 Surface Area Find the surface area of the sphere given the area of the great circle. A 201.1 in2
Example 2 Surface Area Find the surface area of the hemisphere. 4.2 cm
Example 3 Surface Area BASEBALL Find the surface area of a baseball with a circumference of 9 inches to determine how much leather is needed to cover the ball.